career as computational seismologist

Dear Mechanicians,

I have got an offer to do PhD in computational seismology in a very good university in Europe, however, I have no idea what sort of career I should expect after getting my PhD in this field. I got my BSc and MSc in mechanical engineering but have never worked in the field of geophysics and seismology. Therefore I am hesitating whether to take the offer or not. 

Could some of you help me to get a better image of what a computational seismologist would do. Is the career restricted to universities and national seismological service centers? Do you think the market for such field is more restricted than for e.g. mechanical enginerring?

Thank you!

Pegah